Vigorous Days not counted well?

I was told you have to maintain 5 minutes of vigorous minutes at a time for a “vigorous day” to be counted.  So if you’re running then walking then running etc, if your HR drops below 70% of MHR (220-age)*.7 then it won’t count it.  Seems like this is counter-intuitive to HIIT training though.

Normally I take a water break for about 15 seconds every 5 minutes which lowers my HR.  I guess I need to increase the vigorous time to 6 minutes so when I take the water break I still get the 5 minutes counted.

This new update is pure trash considering the fact that Garmin watches often can not record continuously your accurate HR meaning there might be some short time frame where your HR could go from 150 to 90 then back up to 150. After this update my fitness age went from 22.5 to 27.5. Nothing has changed in my own training program during this period of time.